Fluidized coking with catalytic gasification

ABSTRACT

Systems and methods are provided for integrating a fluidized coking process with a catalyst-enhanced coke gasification process. The catalyst for the gasification process can correspond to calcium oxide, a thermally decomposable calcium salt, a potassium salt such as potassium carbonate, or a combination thereof. Examples of suitable calcium salts can include, but are not limited to, calcium hydroxide, calcium nitrate, and calcium carbonate. The calcium oxide, potassium salts, and/or thermally decomposable calcium salts can be introduced into the integrated system, for example, as part of the feed into the coker. It has been unexpectedly discovered that using catalytic gasification as part of an integrated fluidized coking and gasification process can result in an overhead gas stream from the gasifier with increased energy content and/or overhead gas pressure.

FIELD

Systems and methods are provided for integration of fluidized cokingwith catalytic gasification processes.

BACKGROUND

Coking is a carbon rejection process that is commonly used for upgradingof heavy oil feeds and/or feeds that are challenging to process, such asfeeds with a low ratio of hydrogen to carbon. In addition to producing avariety of liquid products, typical coking processes can also generate asubstantial amount coke. Because the coke contains carbon, the coke ispotentially a source of additional valuable products in a refinerysetting. However, fully realizing this potential remains an ongoingchallenge.

Coking processes in modern refinery settings can typically becategorized as delayed coking or fluidized bed coking. Fluidized bedcoking is a petroleum refining process in which heavy petroleum feeds,typically the non-distillable residues (resides) from the fractionationof heavy oils are converted to lighter, more useful products by thermaldecomposition (coking) at elevated reaction temperatures. Heavy oilswhich may be processed by the fluid coking process include heavyatmospheric resides, petroleum vacuum distillation bottoms, aromaticextracts, asphalts, and bitumens from tar sands, tar pits and pitchlakes of Canada (Athabasca, Alta.), Trinidad, Southern California (LaBrea (Los Angeles), McKittrick (Bakersfield, Calif.), Carpinteria (SantaBarbara County, Calif.), Lake Bermudez (Venezuela) and similar depositssuch as those found in Texas, Peru, Iran, Russia and Poland.

The Flexicoking™ process, developed by Exxon Research and EngineeringCompany, is a variant of the fluid coking process that is operated in aunit including a reactor and a heater, but also including a gasifier forgasifying the coke product by reaction with an air/steam mixture to forma low heating value fuel gas. A stream of coke passes from the heater tothe gasifier where all but a small fraction of the coke is gasified to alow-BTU gas (^(˜)120 BTU/standard cubic feet) by the addition of steamand air in a fluidized bed in an oxygen-deficient environment to formfuel gas comprising carbon monoxide and hydrogen. In a conventionalFlexicoking™ configuration, the fuel gas product from the gasifier,containing entrained coke particles, is returned to the heater toprovide most of the heat required for thermal cracking in the reactorwith the balance of the reactor heat requirement supplied by combustionin the heater. A small amount of net coke (about 1 percent of feed) iswithdrawn from the heater to purge the system of metals and ash. Theliquid yield and properties are comparable to those from fluid coking.The fuel gas product is withdrawn from the heater following separationin internal cyclones which return coke particles through their diplegs.

The Flexicoking™ process is described in patents of Exxon Research andEngineering Company, including, for example, U.S. Pat. No. 3,661,543(Saxton), U.S. Pat. No. 3,759,676 (Lahn), U.S. Pat. No. 3,816,084(Moser), U.S. Pat. No. 3,702,516 (Luckenbach), U.S. Pat. No. 4,269,696(Metrailer). A variant is described in U.S. Pat. No. 4,213,848 (Saxton)in which the heat requirement of the reactor coking zone is satisfied byintroducing a stream of light hydrocarbons from the product fractionatorinto the reactor instead of the stream of hot coke particles from theheater. Another variant is described in U.S. Pat. No. 5,472,596 (Kerby)using a stream of light paraffins injected into the hot coke return lineto generate olefins. U.S. Patent Application Publication 2015/0368572provides other examples of systems suitable for use with a Flexicoking™process.

U.S. Pat. No. 8,114,176 describes methods for catalytic steamgasification of petroleum coke to methane. U.S. Pat. No. 6,955,695describes use of separate gas-fired heaters. U.S. Patent ApplicationPublication 2015/0165380 describes catalytic gasification of petroleumcoke using a process that includes impregnation of the coke particleswith alkali metal catalyst. U.S. Patent Application Publication No.2015/0361362 describes a process for catalytic gasification ofcarbonaceous feedstock.

One of the difficulties with performing gasification while reducing orminimizing the amount of slag production is that the resulting low-BTUgas is generated at a low pressure. Thus, although the low-BTU gascontains syngas components (H₂ and/or CO), finding an improved value usefor the low-BTU gas can be difficult due to the combination of lowenergy value and low pressure. What is needed are systems and/or methodsthat can allow for operation of a gasifier under conditions that resultin reduced or minimized gasifier slag formation while also providing asyngas-containing product having improved value.

SUMMARY

In various aspects, a method for performing fluidized coking on a feedis provided. The methods include exposing a feedstock comprising a T10distillation point of 343° C. or more to a fluidized bed comprisingsolid particles in a reactor under coking conditions to form a cokereffluent. The exposing can further include introducing potassiumcarbonate, calcium oxide, one or more thermally decomposable calciumsalts, or a combination thereof into the fluidized bed comprising solidparticles. The potassium carbonate, calcium oxide, and/or calcium saltscan be introduced as part of the feedstock or as separate catalystparticles. The thermal cracking conditions can be selected to provide 10wt % or more conversion of the feedstock relative to 343° C. The methodfurther includes introducing an oxygen-containing stream and steam intoa gasifier stage. The method can also include passing at least a portionof the solid particles including deposited coke from the reactor to thegasifier. After passing the solid particles including deposited cokeinto the gasifier, the solid particles including deposited coke can beexposed to gasification conditions in the presence of potassiumcarbonate, calcium oxide, or a combination thereof to form partiallygasified solid particles and a gas phase product comprising H₂, CO, andCO₂. It is noted that any thermally decomposable calcium saltsintroduced into the fluidized bed can thermally decompose to formcalcium oxide under the coking conditions and/or the gasificationconditions. The gasification conditions can include a temperature of1200° F. to 1400° F. (˜650° C. to ˜760° C.) and a pressure of 20 psig to600 psig (˜140 kPa-g to ˜4100 kPa-g). After gasification, at least afirst portion of the partially gasified solid particles can be removedfrom the gasifier. At least a second portion of the partially gasifiedsolid particles can be passed from the gasifier to the reactor.

In some aspects, the solid particles can correspond to coke particles.In such aspects, at least a portion of the potassium carbonate, calciumoxide, or a combination thereof can be deposited on the at least aportion of the solid particles, the first portion of the partiallygasified solid particles, and/or the second portion of the partiallygasified solid particles.

In some aspects, at least a portion of the potassium carbonate, calciumoxide, one or more thermally decomposable calcium salts, or acombination thereof can be entrained in the feedstock. Additionally oralternately, at least a portion of the potassium carbonate, calciumoxide, one or more thermally decomposable calcium salts can be passedinto the fluidized bed in a carrier fluid different from the feedstockand/or a carrier fluid included in a second and/or additional portion ofthe feedstock. Further additionally or alternately, at least a portionof the potassium carbonate, calcium oxide, or combination thereof cancorrespond to supported potassium catalyst particles, supported calciumcatalyst particles, or a combination thereof. The calcium oxide on thesupported particles can optionally correspond to calcium oxide formed bythermal decomposition of a thermally decomposable calcium salt. Invarious aspects, the one or more thermally decomposable calcium saltscan correspond to calcium nitrate, calcium carbonate, calcium hydroxide,or a combination thereof. In various aspects, the feedstock can include0.01 wt % to 0.5 wt % of the potassium carbonate, calcium oxide, one ormore thermally decomposable calcium salts, or a combination thereof.

In various aspects, a system for performing fluidized coking is alsoprovided. The system includes a fluidized bed coker. The fluidized bedcoker includes a reactor, a reactor coker feed inlet, a reactor coldcoke outlet, a reactor hot coke inlet, a reactor liquid product outlet,and a fluidized bed of solid particles within the reactor. The fluidizedbed of solid particles can include a first portion of solid particleshaving potassium carbonate, calcium oxide, or a combination thereofsupported on the first portion of solid particles. The system canfurther include a gasifier comprising a gasifier coke inlet in fluidcommunication with the cold coke outlet, a gasifier coke outlet in fluidcommunication with the hot coke inlet, at least one gasifier input gasinlet, a fuel gas outlet, and a second portion of solid particles.

In some aspects, the first portion of solid particles can correspond tocoke particles and/or the second portion of solid particles cancorrespond to partially gasified coke particles. In some aspects, thefirst portion of solid particles can correspond to potassium carbonate,calcium oxide, or a combination thereof supported on a refractory oxidesupport.

In some aspects, the reactor can include a coking zone and a strippingzone. In such aspects, the gasifier coke outlet can be in fluidcommunication with the coking zone via the hot coke inlet. Additionallyor alternately, the gasifier coke outlet can be in fluid communicationwith the stripping zone via the hot coke inlet.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example of a fluidized bed coking system including acoker, a heater, and a gasifier that is suitable for performing cokingand catalytic gasification as described herein.

FIG. 2 shows another example of a fluidized bed coking system includinga coker and a gasifier.

FIG. 3 shows another example of a fluidized bed coking system includinga coker and a gasifier.

DETAILED DESCRIPTION

All numerical values within the detailed description and the claimsherein are modified by “about” or “approximately” the indicated value,and take into account experimental error and variations that would beexpected by a person having ordinary skill in the art.

Overview

In various aspects, systems and methods are provided for integrating afluidized coking process with a catalyst-enhanced coke gasificationprocess. The catalyst for the gasification process can correspond tocalcium oxide, a thermally decomposable calcium salt, a potassium saltsuch as potassium carbonate, or a combination thereof. Examples ofsuitable calcium salts can include, but are not limited to, calciumhydroxide, calcium nitrate, and calcium carbonate. The calcium oxide,potassium salts, and/or thermally decomposable calcium salts can beintroduced into the integrated system, for example, as part of the feedinto the coker. It has been unexpectedly discovered that using catalyticgasification as part of an integrated fluidized coking and gasificationprocess can result in an overhead gas stream from the gasifier withincreased energy content and/or overhead gas pressure. Furtheradditionally or alternately, performing catalytic gasification canincrease the relative benefits of integrating fluidized coking withgasification in a two-reactor configuration, as opposed to a traditionalthree-reactor configuration.

Introducing a catalyst into the gasification process can allow thegasifier to operate at a temperature of roughly 1200° F. (˜650° C.) to1400° F. (˜760° C.). This temperature range is in contrast to thetemperature range of ˜870° C. to ˜1100° C. that can typically be usedfor configurations involving a fluidized coker that is thermallyintegrated with a gasifier.

One of the difficulties with using petroleum coke, coal, and/or heavyoils as a feed for gasification is that such feeds can potentiallycontain a relatively high percentage of transition metals, such as iron,nickel, and vanadium. During conventional operation of a gasifier thatcan individually maintain heat balance (i.e., a gasifier that performssufficient combustion of carbon with oxygen to at least maintain thegasifier temperature), these transition metals can be converted into a“slag” that tends to be corrosive for the internal structures of thegasifier. As a result, such gasifiers can typically have relativelyshort operating lengths between shutdown events, such as operatinglengths of roughly 3 months to 18 months. For a gasifier that operatesin a stand-alone manner, frequent shutdown events may be acceptable.However, for a gasifier that is integrated to provide heat balance toanother process, such as a fluidized bed coker, a short cycle length forthe gasifier can force a short cycle length for the coker as well.

It is noted that one option for reducing or minimizing slag formationcan be to use gasification conditions that include little or no oxygen.However, gasifiers operated under such conditions typically need to bepaired with an additional heat source that can provide heat to thegasifier in order to maintain heat balance during operation. Theadditional heat source can correspond to a gas-fired heater, acombustor, or another unit that can generate heat for transfer into thegasification environment. Such an additional heat source can be lessdesirable due to the need for additional refinery footprint and/or theconsumption of additional refinery resources.

In order to overcome the problems related to slag formation, a gasifierthat is thermally integrated with a fluidized bed coking process, suchas a Flexicoking™ process, can be operated under conditions that reduce,minimize, or eliminate formation of slag while still providing excessheat to the fluidized coking process. This can be achieved, for example,by using a gasification process that includes air as at least a portionof the oxygen source for the gasifier. The additional nitrogen in aircan provide a diluent for the gasifier environment that can reduce orminimize slag formation. Instead of forming a slag or other glassy typeproduct containing metals, the metals in the coke can be retained incoke form and purged from the integrated system. This can allow theremoval/disposition of the metals to be performed in a secondary deviceor location. By avoiding formation of the corrosive slag, the cyclelength of the integrated coker and gasifier can be substantiallyimproved. Additionally, operating the gasifier in such a manner canavoid the need to include an additional combustor and/or gas-firedheater as a heat source for maintaining heat balance.

One difficulty with operating an integrated coker and gasifier to avoidslag formation is that the resulting gas phase product generated in thegasifier can have a relatively low BTU value. Because of the substantialamount of nitrogen introduced into the gasifier along with the oxygen,the nitrogen content of the gas phase product generated from a gasifierin an integrated fluidized bed/gasifier system can be up to 55 vol %.This can present a variety of problems when attempting to find a highvalue use for the carbon in the gas phase product from the gasifier. Forexample, this gas phase product includes a sufficient amount of diluent(such as nitrogen) that it is not directly suitable as a fuel in varioustypes of burners in a refinery setting. Instead, use of the gas phaseproduct as a fuel may require distribution of the gas phase productacross multiple burners, so that the gas phase product can be blendedwith other fuels having a higher energy density. Another difficulty isthat the gas phase product is also a low pressure stream when it emergesfrom the gasifier. Attempting to compress the gas phase product from thegasifier to match pressures in another processing environment wouldrequire compressing the substantial amount of nitrogen in the product,meaning a substantial additional compression cost with little value inreturn.

It has been unexpectedly discovered that performing gasification undercatalytic gasification conditions can increase the energy content and/orincrease the pressure of the gas phase product stream generated by thegasifier. In some aspects, a portion of the benefit of performingcatalytic gasification can be an increase in the amount of syngasgenerated in the gasifier relative to the amount of input steam,nitrogen, and oxygen. Additionally or alternately, the amount of methanegenerated in the gasifier can be increased. Further additionally oralternately, the resulting pressure of the overhead gas phase productstream generated by the gasifier can be increased. Due in part to thelower gasification temperature that can be used during catalyticgasification, a higher pressure can be used within the gasifier whilestill reducing or minimizing the amount of slag formation. The higherpressure for the gasification conditions can result in a correspondinghigher pressure for the gas phase product (sometimes referred to as“low-BTU” gas) generated by the gasification process.

Catalytic Gasification

In various aspects, gasification of coke can be performed in thepresence of a catalyst that includes potassium, calcium, or acombination thereof. The potassium, calcium, or combination thereof canbe in any convenient oxidation state that can result from exposure ofthe initial potassium-containing and/or calcium-containing compound(s)to the gasification environment. For example, a catalyst includingpotassium carbonate can remain in a potassium carbonate form within thecoker and/or gasifier. Calcium carbonate or calcium hydroxide can tendto decompose under the conditions present in a coker and/or gasifier toform calcium oxide and an additional gas phase product based on thestoichiometry of the initial calcium salt.

In some aspects, the catalyst including potassium, calcium, or acombination thereof can be introduced into the reaction system as asolid suspended and/or dissolved in the feed to the fluidized coker. Insuch aspects, the catalyst can be mixed with the feed at any convenienttime prior to introducing the feed into the fluidized cokingenvironment. Additionally or alternately, a portion of the catalyst canbe introduced into the fluidized coking environment in a hydrocarbon (orhydrocarbon-like) carrier stream that is separate from the feed to thefluidized coker. In such additional or alternate aspects, any convenientcarrier can be used that allows the catalyst to be introduced into thefluidized coking environment for eventual deposition on coke particles.After introduction into the fluidized coking environment as part of thefeed and/or in a separate carrier stream, the calcium oxide (optionallyformed by thermal decomposition) or potassium salt can be deposited on(or otherwise incorporated into) coke particles that are circulatedbetween the coker and the gasifier. The coke particles can thus serve asa “substrate” for support of the calcium oxide or potassium salt.

In aspects where the coke particles serve as a “substrate” for supportof at least a portion of the catalyst, a reduced or minimized amount ofcatalyst can be used to catalyze the gasification process. In aconventional coke gasification process based on gasification of cokefrom a delayed coker, the coke particles are typically completelyconsumed during either gasification or an associated combustion process.By contrast, in a gasification process as described herein, the cokeparticles are only partially gasified in the gasifier, and then returnedto the coker for accumulation of additional coke. A small portion of thecoke particles are withdrawn from the reaction system as a purge streamto remove ash, metals, and/or other non-combustible materials that mightpotentially contribute to formation of slag or other deposits within thegasifier. Because only a small portion of the coke is removed via thepurge stream during each cycle through the coker and gasifier, themajority of the catalyst supported on the coke can be retained in thecombined fluidized coker and gasifier reaction system. As a result, theamount of catalyst introduced into the gasifier can be unexpectedlylower than the amount of catalyst used in a conventional catalyticgasifier. In various aspects, the amount of catalyst introduced with thefeed into the fluidized coker can correspond to from 0.01 wt % to 0.5 wt% of the feed, or 0.01 wt % to 0.3 wt %, or 0.1 wt % to 0.5 wt %, or 0.1wt % to 0.3 wt %. Optionally, the catalyst removed from the reactor viathe purge stream can be recovered by any convenient method, such as foruse as recycled catalyst.

In other aspects, the catalyst including potassium, calcium, or acombination thereof can be introduced into the reactor in the form of asupported catalyst. For example, one or more potassium and/or calciumcompounds can be supported on a refractory oxide substrate, such as analumina substrate. In such aspects, the catalyst particles can be passedbetween the coker and gasifier along with the coke particles. A portionof the catalyst particles can also be withdrawn as part of the purgestream from the gasifier. Such catalyst particles can be recovered, andoptionally recycled for further use.

Example of Configuration for Fluidized Coking with IntegratedGasification

In this description, the term “Flexicoking” (trademark of ExxonMobilResearch and Engineering Company) is used to designate a fluid cokingprocess in which heavy petroleum feeds are subjected to thermal crackingin a fluidized bed of heated solid particles to produce hydrocarbons oflower molecular weight and boiling point along with coke as a by-productwhich is deposited on the solid particles in the fluidized bed. Theresulting coke can then converted to a gas phase product by contact atelevated temperature with steam and an oxygen-containing gas in agasification reactor (gasifier). This type of configuration can moregenerally be referred to as an integration of fluidized bed coking withgasification.

In various aspects, an integrated fluidized bed coker and gasifier,optionally also including a heater, can be used to process a feed byfirst coking the feed and then gasifying the resulting coke. This cangenerate a gas phase product, withdrawn from the gasifier or theoptional heater, that can then be further processed to increase theconcentration of synthesis gas in the product. The product withincreased synthesis gas concentration can then be used as an input forproduction of methanol, optionally after further processing to adjustthe H₂ to CO ratio in the synthesis gas.

FIG. 1 shows an example of a Flexicoker unit (i.e., a system including agasifier that is thermally integrated with a fluidized bed coker) withthree reaction vessels: reactor, heater and gasifier. It is noted thatthere may be some advantages to using catalytic gasification in areaction system that does not include a separate heater (as furtherillustrated in FIG. 2), but catalytic gasification can also becompatible for use in a system that includes a heater in a thirdreaction vessel. In the example shown in FIG. 1, the unit comprisesreactor section 10 with the coking zone and its associated stripping andscrubbing sections (not separately indicated), heater section 11 andgasifier section 12. The relationship of the coking zone, scrubbing zoneand stripping zone in the reactor section is shown, for example, in U.S.Pat. No. 5,472,596, to which reference is made for a description of theFlexicoking unit and its reactor section. A heavy oil feed is introducedinto the unit by line 13 and cracked hydrocarbon product withdrawnthrough line 14. Fluidizing and stripping steam is supplied by line 15.Cold coke is taken out from the stripping section at the base of reactor10 by means of line 16 and passed to heater 11. The term “cold” asapplied to the temperature of the withdrawn coke is, of course,decidedly relative since it is well above ambient at the operatingtemperature of the stripping section. Hot coke is circulated from heater11 to reactor 10 through line 17. Coke from heater 11 is transferred togasifier 12 through line 21 and hot, partly gasified particles of cokeare circulated from the gasifier back to the heater through line 22. Theexcess coke is withdrawn from the heater 11 by way of line 23. Inconventional configurations, gasifier 12 is provided with its supply ofsteam and air by line 24 and hot gas phase product is taken from thegasifier to the heater though line 25. In some alternative aspects,instead of supplying air via a line 24 to the gasifier 12, a stream ofoxygen with 95 vol % purity or more can be provided, such as an oxygenstream from an air separation unit. In such aspects, in addition tosupplying a stream of oxygen, a stream of an additional diluent gas canbe supplied by line 31. The additional diluent gas can correspond to,for example, CO₂ separated from the fuel gas generated during thegasification. The gas phase product is taken out from the unit throughline 26 on the heater; coke fines are removed from the gas phase productin heater cyclone system 27 comprising serially connected primary andsecondary cyclones with diplegs which return the separated fines to thefluid bed in the heater. The gas phase product from line 26 can thenundergo further processing. For example, in some aspects, the gas phaseproduct from line 26 can be passed into a separation stage forseparation of CO₂ (and/or H₂S). This can result in a stream with anincreased concentration of synthesis gas, which can then be passed intoa conversion stage for conversion of synthesis gas to methanol.

It is noted that in some optional aspects, heater cyclone system 27 canbe located in a separate vessel (not shown) rather than in heater 11. Insuch aspects, line 26 can withdraw the gas phase product from theseparate vessel, and the line 23 for purging excess coke can correspondto a line transporting coke fines away from the separate vessel. Thesecoke fines and/or other partially gasified coke particles that arevented from the heater (or the gasifier) can have an increased contentof metals relative to the feedstock. For example, the weight percentageof metals in the coke particles vented from the system (relative to theweight of the vented particles) can be greater than the weight percentof metals in the feedstock (relative to the weight of the feedstock). Inother words, the metals from the feedstock are concentrated in thevented coke particles. Since the gasifier conditions create little or noslag, the vented coke particles correspond to the mechanism for removalof metals from the coker/gasifier environment. In some aspects, themetals can correspond to a combination of nickel, vanadium, and/or iron.Additionally or alternately, the gasifier conditions can causesubstantially no deposition of metal oxides on the interior walls of thegasifier, such as deposition (cumulative weight in the form of metaloxides) of less than 0.1 wt % of the metals present (cumulative weight)in the feedstock introduced into the coker/gasifier system, or less than0.01 wt %.

In configurations such as FIG. 1, the system elements shown in thefigure can be characterized based on fluid communication between theelements. For example, reactor section 10 is in direct fluidcommunication with heater 11. Reactor section 10 is also in indirectfluid communication with gasifier 12 via heater 11.

Integration of a fluidized bed coker with a gasifier can also beaccomplished without the use of an intermediate heater. In such aspects,the cold coke from the reactor can be transferred directly to thegasifier. This transfer, in almost all cases, will be direct with oneend of the tubular transfer line connected to the coke outlet of thereactor and its other end connected to the coke inlet of the gasifierwith no intervening reaction vessel, i.e. heater. The presence ofdevices other than the heater is not however to be excluded, e.g. inletsfor lift gas etc. Similarly, while the hot, partly gasified cokeparticles from the gasifier are returned directly from the gasifier tothe reactor this signifies only that there is to be no interveningheater as in the conventional three-vessel Flexicoker™ but that otherdevices may be present between the gasifier and the reactor, e.g. gaslift inlets and outlets.

FIG. 2 shows an example of integration of a fluidized bed coker with agasifier but without a separate heater vessel. In the configurationshown in FIG. 2, the gasifier corresponds to a single gasifier reactor,although the cyclones for separating the gas phase product from catalystfines are located in a separate vessel. In other aspects, the cyclonescan be included in gasifier vessel 41 (i.e., in the single gasifierreactor).

In the configuration shown in FIG. 2, the configuration includes areactor 40, a main gasifier vessel 41 and a separator 42. The heavy oilfeed is introduced into reactor 40 through line 43 andfluidizing/stripping gas through line 44; cracked hydrocarbon productsare taken out through line 45. Cold, stripped coke is routed directlyfrom reactor 40 to gasifier 41 by way of line 46 and hot coke returnedto the reactor in line 47. Steam and oxygen are supplied through line48. The flow of gas containing coke fines is routed to separator vessel42 through line 49 which is connected to a gas outlet of the maingasifier vessel 41. The fines are separated from the gas flow in cyclonesystem 50 comprising serially connected primary and secondary cycloneswith diplegs which return the separated fines to the separator vessel.The separated fines are then returned to the main gasifier vesselthrough return line 51 and the gas phase product taken out by way ofline 52. Coke is purged from the separator through line 53. The gasphase product from line 52 can then undergo further processing forseparation of CO₂ (and/or H₂S) and conversion of synthesis gas tomethanol.

FIG. 3 schematically shows some additional details regarding use ofcatalytic gasification as part of an integrated fluidized coking andgasification reaction system. In FIG. 3, a feed 301 suitable for cokingis introduced into fluidized bed coker 312. In the example shown in FIG.3, prior to the feed 301 entering the coker 312, catalyst 311 forcatalytic gasification can be added to feed 301. At startup, a largeramount of catalyst 311 may be added in the feed in order to achieve adesired catalyst concentration within the gasifier. After steady-stateoperation has been achieved, the catalyst 311 added to feed 301 cancorrespond to a “make-up” amount of catalyst, as purge stream 362 willtypically include a relatively small amount of catalyst relative to thecatalyst inventory in the reaction system. The reactor or coking section317 and stripper section 318 of fluidized bed coker 312 are shown inFIG. 3. The feed 301 can correspond to a heavy oil feed, or any otherconvenient feed typically used as an input for a coker. In theconfiguration shown in FIG. 3, the fluidized bed coker 312 is integratedwith a catalytic gasifier 316. This combination of elements is similarto the configuration shown in FIG. 2. In other aspects, the fluidizedbed coker can be integrated with both a heater and a gasifier.

In FIG. 3, fluidized bed coker 312 generates a coker effluent 305 thatincludes fuel boiling range liquids generated during the coking process.Heat for coker 312 can be provided by hot coke recycle line 376 andsecond hot coke recycle line 386 from gasifier 316. In the configurationshown in FIG. 3, the hot coke recycle line 376 from catalytic gasifier316 is passed into coking section 317 of coker 312. The second hot cokerecycle line 386 from gasifier 316 is passed into stripping section 318of coker 312. This can provide separate control of the heating in thecoking section 317 and stripping section 318 of coker 312. In otheraspects, any convenient number and combination of hot coke recycle linesfrom the gasifier 316 can be used to provide heat to coker 312. Forexample, in some configurations, only one hot coke recycle line may bepresent, so that hot coke is returned only to the stripping section 318or only to the reactor section 316.

Cold coke from coker 312 is passed into gasifier 316 via line 324. Asnoted above partly gasified particles of coke are circulated from thegasifier back to the coker 312 through line 376 and/or 386. A gas phaseproduct generated in gasifier 316 can exit as gas phase product stream321. The gas phase product 321 can include H₂, CO, CO₂ (i.e., componentsof syngas), as well as methane and optionally other light ends. The gasphase product 321 can also include any diluent gases introduced into thereaction system, such as N₂ that can be introduced when air is used asthe oxygen source for the gasifier. It is noted that gasifier 316 doesnot generate a slag that is separately removed from the gasifier.Instead, excess coke is withdrawn from the gasifier 316 as a purgestream 362. Optionally, one or more catalyst recovery processes can beperformed on purge stream 362 to recover the calcium- or potassium-basedcatalyst. The nature of the catalyst recovery can be dependent on thetype of catalyst used in the catalytic gasifier. Oxygen and steam forthe gasifier are introduced, for example, via line 304.

The coker and gasifier can be operated according to the parametersnecessary for the required coking processes. Thus, the heavy oil feedwill typically be a heavy (high boiling) reduced petroleum crude;petroleum atmospheric distillation bottoms; petroleum vacuumdistillation bottoms, or residuum; pitch; asphalt; bitumen; other heavyhydrocarbon residues; tar sand oil; shale oil; or even a coal slurry orcoal liquefaction product such as coal liquefaction bottoms. Such feedswill typically have a Conradson Carbon Residue (ASTM D189-165) of atleast 5 wt. %, generally from 5 to 50 wt. %. Preferably, the feed is apetroleum vacuum residuum.

A typical petroleum chargestock suitable for processing in a fluidizedbed coker can have a composition and properties within the ranges setforth below in Table 1.

TABLE 1 Example of Coker Feedstock Conradson Carbon 5 to 40 wt. % APIGravity −10 to 35°  Boiling Point 340° C.+ to 650° C.+ Sulfur 1.5 to 8wt. % Hydrogen 9 to 11 wt % Nitrogen 0.2 to 2 wt. % Carbon 80 to 86 wt.% Metals 1 to 2000 wppm

More generally, the feed to the fluidized bed coker can have a T10distillation point of 343° C. or more, or 371° C. or more.

The heavy oil feed, pre-heated to a temperature at which it is flowableand pumpable, is introduced into the coking reactor towards the top ofthe reactor vessel through injection nozzles which are constructed toproduce a spray of the feed into the bed of fluidized coke particles inthe vessel. Temperatures in the coking zone of the reactor are typicallyin the range of 450° C. to 850° C. and pressures are kept at arelatively low level, typically in the range of 120 kPag to 400 kPag(˜17 psig to 58 psig), and most usually from 200 kPag to 350 kPag (˜29psig to 51 psig), in order to facilitate fast drying of the cokeparticles, preventing the formation of sticky, adherent high molecularweight hydrocarbon deposits on the particles which could lead to reactorfouling. The conditions can be selected so that a desired amount ofconversion of the feedstock occurs in the fluidized bed reactor. Forexample, the conditions can be selected to achieve at least 10 wt %conversion relative to 343° C. (or 371° C.), or at least 20 wt %conversion relative 343° C. (or 371° C.), or at least 40 wt % conversionrelative to 343° C. (or 371° C.), such as up to 80 wt % conversion orpossibly still higher. The light hydrocarbon products of the coking(thermal cracking) reactions vaporize, mix with the fluidizing steam andpass upwardly through the dense phase of the fluidized bed into a dilutephase zone above the dense fluidized bed of coke particles. This mixtureof vaporized hydrocarbon products formed in the coking reactions flowsupwardly through the dilute phase with the steam at superficialvelocities of roughly 1 to 2 meters per second (˜3 to 6 feet persecond), entraining some fine solid particles of coke which areseparated from the cracking vapors in the reactor cyclones as describedabove. The cracked hydrocarbon vapors pass out of the cyclones into thescrubbing section of the reactor and then to product fractionation andrecovery.

As the cracking process proceeds in the reactor, the coke particles passdownwardly through the coking zone, through the stripping zone, whereoccluded hydrocarbons are stripped off by the ascending current offluidizing gas (steam). They then exit the coking reactor and pass tothe gasification reactor (gasifier) which contains a fluidized bed ofsolid particles and which operates at a temperature higher than that ofthe reactor coking zone. In the gasifier, the coke particles areconverted by reaction at the elevated temperature with steam and anoxygen-containing gas into a gas phase product comprising carbonmonoxide and hydrogen.

During catalytic gasification, the gasification zone can be maintainedat a temperature ranging from 650° C. to 760° C. (˜1200° F. to 1400° F.)and a pressure ranging from roughly 140 kPa-g to 4100 kPa-g (˜20 psig to˜600 psig), preferably from roughly 1350 kPa-g to 4100 kPa-g (˜200 psigto 600 psig). Steam and an oxygen-containing gas are introduced toprovide fluidization and an oxygen source for gasification. In someaspects the oxygen-containing gas can be air. In other aspects, theoxygen-containing gas can have a low nitrogen content, such as oxygenfrom an air separation unit or another oxygen stream including 95 vol %or more of oxygen, or 98 vol % or more, are passed into the gasifier forreaction with the solid particles comprising coke deposited on them inthe coking zone. In aspects where the oxygen-containing gas has a lownitrogen content, a separate diluent stream, such as a recycled CO₂ orH₂₅ stream derived from the gas phase product produced by the gasifier,can also be passed into the gasifier.

In the gasification zone the reaction between the coke and the steam andthe oxygen-containing gas produces a hydrogen and carbonmonoxide-containing gas phase product and a partially gasified residualcoke product. Conditions in the gasifier are selected accordingly togenerate these products. Steam and oxygen rates (as well as any optionalCO₂ rates) will depend upon the rate at which cold coke enters from thereactor and to a lesser extent upon the composition of the coke which,in turn will vary according to the composition of the heavy oil feed andthe severity of the cracking conditions in the reactor with these beingselected according to the feed and the range of liquid products which isrequired. The gas phase product from the gasifier may contain entrainedcoke solids and these are removed by cyclones or other separationtechniques in the gasifier section of the unit; cyclones may be internalcyclones in the main gasifier vessel itself or external in a separate,smaller vessel as described below. The gas phase product is taken out asoverhead from the gasifier cyclones. The resulting partly gasifiedsolids are removed from the gasifier and introduced directly into thecoking zone of the coking reactor at a level in the dilute phase abovethe lower dense phase.

In aspects where a separate heater is present, such as in the exampleconfiguration shown in FIG. 1, the pressure of the heater can be similarto the pressure in the gasifier. The temperature in the heater can besimilar to the temperature in the gasifier, or the temperature in theheater can be between the temperature of the fluidized coker and thetemperature of the gasifier.

Example: Gas Phase Product Generated During Catalytic Gasification

Non-catalytic and catalytic gasification were performed in agasification stage using coke generated in a fluidized coker. Thegasification stage included separate reactors for steam gasification andair gasification. The rate of introduction of coke into the gasificationstage was selected to be representative of the flow rate during anintegrated fluidized coking and gasification process (such as a with agasifier corresponding to a single gasifier reactor). Air was used asthe oxygen source for the gasifier. For the conventional (non-catalytic)gasification, the temperature of the steam in the steam gasifier was1600° F. (˜870° C.) while the temperature of the steam for the catalyticgasification was 1300° F. (˜705° C.). The pressure was between 1350kPa-g and 4100 kPa-g. The temperature of the oxygen-containing stream(air) introduced into both air gasification reactors was constant atroughly 1700° F. (˜925° C.). For the catalytic gasification, the cokefeed to the gasifier included 1 wt % of calcium oxide. This is believedto be representative of the amount of calcium oxide that would bepresent at steady-state during operation of an integrated fluidizedcoker and catalytic gasifier as described herein, with a catalystaddition rate of 0.01-0.5 wt % of feed.

Table 2 shows additional details regarding the operating conditions forthe gasifiers and the resulting gas phase products generated by thegasifiers. In Table 2, the amounts of product gases are reported basedon the heating value (in BTUs) of the gases. In Table 2, syngas wasdefined as having a ratio of H₂ to CO of 2.1. Any excess H₂ or COdifferent from this defined ratio was accounted for as part of the LowBTU gas. For the relative syngas amounts in the final two lines of Table2, the amount of syngas generated by the traditional gasificationprocess was used as a baseline, and thus has a relative value of 1.

TABLE 2 Traditional and Catalytic Gasification of Coke Type ofgasification Traditional Catalytic Steam Temperature (° C.) ~870 ~705Air Temperature (° C.) ~925 ~925 Total Syngas (MBTU/hr) 282 314 CH₄ inSyngas (MBTU/hr) 1 8 LBG Rate (MBTU/hr) 73 60 Total Product Rate(MBTU/hr) 355 374 % Total Heat in Syngas 80 84 % Gross Coke SteamGasified 50 56 Relative Syngas (MBTU/hr) 1.00 1.11

In Table 2, the total heating value of gases is increased when usingcatalytic gasification. This includes an increase in the amounts ofsyngas (at a H₂:CO ratio of 2.1) and methane. The heating value of theremaining low BTU gas (LBG) includes any H₂ and CO not accounted for assyngas, as well as the methane noted in Table 1. As shown in Table 1,the heating value of syngas generated during catalytic gasification isincreased by roughly 10% relative to the corresponding heating value ofsyngas generated by conventional gasification. Similarly, the heatingvalue of the total product from catalytic gasification was increased byroughly 5% relative to the traditional gasification process.Additionally, the syngas includes an increased amount of methane. Theamount of coke gasified under the steam gasification conditions is alsoincreased, due in part to the increased pressure that can be used in thegasifier under catalytic gasification conditions.

It is noted that the catalytic gasification process described in thisexample can also be performed using a gasifier corresponding to a singlegasifier reactor. In such an aspect, both steam and air are can beintroduced into the gasifier. This results in production of a gas phaseproduct that includes synthesis gas, but that also includes at least aportion of the N₂ introduced into the gasifier as part of the air.

Additional Embodiments Embodiment 1

A method for performing fluidized coking on a feed, comprising: exposinga feedstock comprising a T10 distillation point of 343° C. or more to afluidized bed comprising solid particles in a reactor under cokingconditions to form a coker effluent, the thermal cracking conditionscomprising 10 wt % or more conversion of the feedstock relative to 343°C., the thermal cracking conditions being effective for depositing cokeon the solid particles, wherein the exposing further comprisesintroducing potassium carbonate, calcium oxide, one or more thermallydecomposable calcium salts, or a combination thereof into the fluidizedbed comprising solid particles; introducing an oxygen-containing streamand steam into a gasifier stage, the oxygen-containing stream optionallycomprising air; passing at least a portion of the solid particlescomprising deposited coke from the reactor to the gasifier; exposing theat least a portion of the solid particles comprising deposited coke togasification conditions in the presence of at least a portion of thesteam, oxygen from the oxygen-containing stream, and potassiumcarbonate, calcium oxide, or a combination thereof to form partiallygasified solid particles and a gas phase product comprising H₂, CO, andCO₂, the gasification conditions comprising a temperature of 1200° F. to1400° F. (˜650° C. to ˜760° C.) and a pressure of 20 psig to 600 psig(˜140 kPa-g to ˜4100 kPa-g);

removing at least a first portion of the partially gasified solidparticles from the gasifier; and passing at least a second portion ofthe partially gasified solid particles from the gasifier to the reactor,the gasifier optionally comprising a single gasifier reactor, theoxygen-containing stream optionally comprising air.

Embodiment 2

The method of Embodiment 1, wherein the solid particles comprise cokeparticles, and optionally wherein at least a portion of the potassiumcarbonate, calcium oxide, or combination thereof comprises potassiumcarbonate, calcium oxide, or a combination thereof deposited on i) theat least a portion of the solid particles, ii) the first portion of thepartially gasified solid particles, iii) the second portion of thepartially gasified solid particles, or iv) a combination thereof.

Embodiment 3

The method of any of the above embodiments, wherein the potassiumcarbonate, calcium oxide, one or more thermally decomposable calciumsalts, or a combination thereof is entrained in the feedstock.

Embodiment 4

The method of any of the above embodiments, wherein introducingpotassium carbonate, calcium oxide, one or more thermally decomposablecalcium salts, or a combination thereof into the fluidized bed of solidparticles comprises: introducing the potassium carbonate, calcium oxide,one or more thermally decomposable calcium salts, or a combinationthereof into the fluidized bed of solid particles in a carrier fluiddifferent from the feedstock.

Embodiment 5

The method of any of Embodiments 1-3, wherein a second portion of thefeedstock comprises the potassium carbonate, calcium oxide, thermallydecomposable calcium salt, or a combination thereof, the second portionof the feedstock further comprising a carrier fluid.

Embodiment 6

The method of any of the above embodiments, wherein the one or morethermally decomposable calcium salts comprise calcium nitrate, calciumcarbonate, calcium hydroxide, or a combination thereof.

Embodiment 7

The method of any of the above embodiments, wherein the feedstockcomprises 0.01 wt % to 0.5 wt % of the potassium carbonate, calciumoxide, one or more thermally to decomposable calcium salts, or acombination thereof (or 0.01 wt % to 0.3 wt %, or 0.1 wt % to 0.5 wt %,or 0.1 wt % to 0.3 wt %).

Embodiment 8

The method of any of the above embodiments, wherein the potassiumcarbonate, calcium oxide, or combination thereof comprises supportedpotassium catalyst particles, supported calcium catalyst particles, or acombination thereof, the method optionally further comprising recoveringthe supported potassium catalyst particles, the supported calciumcatalyst particles, or a combination thereof and recycling the supportedpotassium catalyst particles, the supported calcium particles, or acombination thereof to at least one of the reactor and the gasifierstage.

Embodiment 9

The method of any of the above embodiments, wherein the cokingconditions comprise a temperature of 950° F. to 1100° F. (˜510° C. to˜595° C.) and a pressure of 20 psig to 600 psig (˜140 kPa-g to ˜4100kPa-g); or wherein the gasification conditions comprise a pressure of200 psig to 600 psig (˜1400 kPa-g to ˜4100 kPa-g); or a combinationthereof.

Embodiment 10

The method of any of the above embodiments, wherein the first portion ofpartially gasified solid particles comprises a first weight percentageof metals (optionally a first combined weight percentage of Ni, V, Fe),relative to a weight of the first portion of partially gasified cokeparticles, that is greater than a weight percentage of metals(optionally a combined weight percentage of Ni, V, Fe) in the feedstock,relative to a weight of the feedstock.

Embodiment 11

The method of any of the above embodiments, wherein the exposing the atleast a portion of the solid particles comprising deposited coke togasification conditions results in cumulative deposition of less than0.1 wt % of metals on the gasifier wall, relative to the feedstock'scumulative metals content.

Embodiment 12

The method of any of the above embodiments, wherein passing at least asecond portion of the partially gasified solid particles from thegasifier to the reactor comprises a) passing at least a second portionof the partially gasified solid particles from the gasifier to a cokingsection of the reactor; b) passing at least a second portion of thepartially gasified solid particles from the gasifier to a strippingsection of the reactor; or c) a combination of a) and b).

Embodiment 13

A system for performing fluidized coking, comprising: a fluidized bedcoker comprising a reactor, a reactor coker feed inlet, a reactor coldcoke outlet, a reactor hot coke inlet, a reactor liquid product outlet,and a fluidized bed of solid particles within the reactor, the fluidizedbed of solid particles comprising a first portion of solid particleshaving potassium carbonate, calcium oxide, or a combination thereofsupported on the first portion of solid particles; and a gasifiercomprising a gasifier coke inlet in fluid communication with the coldcoke outlet, a gasifier coke outlet in fluid communication with the hotcoke inlet, at least one gasifier input gas inlet, a fuel gas outlet,and a second portion of solid particles, the gasifier optionallycomprising a single gasifier reactor.

Embodiment 14

The system of Embodiment 13, wherein the first portion of solidparticles comprises coke particles and/or the second portion of solidparticles comprises partially gasified coke particles; or wherein thefirst portion of solid particles comprise potassium carbonate, calciumoxide, or a combination thereof supported on a refractory oxide support;or a combination thereof.

Embodiment 15

The system of Embodiment 13 or 14, wherein the reactor comprises acoking zone and a stripping zone, wherein a) the gasifier coke outlet isin fluid communication with the coking zone via the hot coke inlet, b)the gasifier coke outlet is in fluid communication with the strippingzone via the hot coke inlet, or c) a combination of a) and b).

When numerical lower limits and numerical upper limits are listedherein, ranges from any lower limit to any upper limit are contemplated.While the illustrative embodiments of the invention have been describedwith particularity, it will be understood that various othermodifications will be apparent to and can be readily made by thoseskilled in the art without departing from the spirit and scope of theinvention. Accordingly, it is not intended that the scope of the claimsappended hereto be limited to the examples and descriptions set forthherein but rather that the claims be construed as encompassing all thefeatures of patentable novelty which reside in the present invention,including all features which would be treated as equivalents thereof bythose skilled in the art to which the invention pertains.

The present invention has been described above with reference tonumerous embodiments and specific examples. Many variations will suggestthemselves to those skilled in this art in light of the above detaileddescription. All such obvious variations are within the full intendedscope of the appended claims.

1. A method for performing fluidized coking on a feed, comprising:exposing a feedstock comprising a T10 distillation point of 343° C. ormore to a fluidized bed comprising solid particles in a reactor undercoking conditions to form a coker effluent, the thermal crackingconditions comprising 10 wt % or more conversion of the feedstockrelative to 343° C., the thermal cracking conditions being effective fordepositing coke on the solid particles, the exposing further comprisingintroducing potassium carbonate, calcium oxide, one or more thermallydecomposable calcium salts, or a combination thereof into the fluidizedbed comprising solid particles; introducing an oxygen-containing streamand steam into a gasifier; passing at least a portion of the solidparticles comprising deposited coke from the reactor to the gasifier;exposing the at least a portion of the solid particles comprisingdeposited coke to gasification conditions in the presence of at least aportion of the steam, oxygen from the oxygen-containing stream, andpotassium carbonate, calcium oxide, or a combination thereof to formpartially gasified solid particles and a gas phase product comprisingHz, CO, and CO₂, the gasification conditions comprising a temperature of1200° F. to 1400° F. (˜650° C. to ˜760° C.) and a pressure of 20 psig to600 psig (˜140 kPa-g to ˜4100 kPa-g); removing at least a first portionof the partially gasified solid particles from the gasifier; and passingat least a second portion of the partially gasified solid particles fromthe gasifier to the reactor.
 2. The method of claim 1, wherein the solidparticles comprise coke particles.
 3. The method of claim 2, wherein atleast a portion of the potassium carbonate, calcium oxide, orcombination thereof comprises potassium carbonate, calcium oxide, or acombination thereof deposited on the at least a portion of the solidparticles, the first portion of the partially gasified solid particles,the second portion of the partially gasified solid particles, or acombination thereof.
 4. The method of claim 1, wherein the potassiumcarbonate, calcium oxide, one or more thermally decomposable calciumsalts, or a combination thereof is entrained in the feedstock.
 5. Themethod of claim 1, wherein introducing potassium carbonate, calciumoxide, one or more thermally decomposable calcium salts, or acombination thereof into the fluidized bed of solid particles comprises:introducing the potassium carbonate, calcium oxide, one or morethermally decomposable calcium salts, or a combination thereof into thefluidized bed of solid particles in a carrier fluid different from thefeedstock.
 6. The method of claim 1, wherein the feedstock comprises afirst portion and a second portion, and wherein the second portion ofthe feedstock comprises the potassium carbonate, calcium oxide,thermally decomposable calcium salt, or a combination thereof, thesecond portion of the feedstock further comprising a carrier fluid. 7.The method of claim 1, wherein the one or more thermally decomposablecalcium salts comprise calcium nitrate, calcium carbonate, calciumhydroxide, or a combination thereof.
 8. The method of claim 1, whereinthe feedstock comprises 0.01 wt % to 0.5 wt % of the potassiumcarbonate, calcium oxide, one or more thermally decomposable calciumsalts, or a combination thereof.
 9. The method of claim 1, wherein thepotassium carbonate, calcium oxide, or combination thereof comprisessupported potassium catalyst particles, supported calcium catalystparticles, or a combination thereof.
 10. The method of claim 9, furthercomprising recovering the supported potassium catalyst particles, thesupported calcium catalyst particles, or a combination thereof andrecycling the supported potassium catalyst particles, the supportedcalcium particles, or a combination thereof to at least one of thereactor and the gasifier.
 11. The method of claim 1, wherein the cokingconditions comprise a temperature of 950° F. to 1100° F. (˜510° C. to˜595° C.) and a pressure of 20 psig to 600 psig (˜140 kPa-g to ˜4100kPa-g).
 12. The method of claim 1, wherein the gasification conditionscomprise a pressure of 200 psig to 600 psig (˜1400 kPa-g to ˜4100kPa-g).
 13. The method of claim 1, wherein the first portion ofpartially gasified solid particles comprises a first weight percentageof metals (optionally a first combined weight percentage of Ni, V, Fe),relative to a weight of the first portion of partially gasified cokeparticles, that is greater than a weight percentage of metals(optionally a combined weight percentage of Ni, V, Fe) in the feedstock,relative to a weight of the feedstock.
 14. The method of claim 1,wherein the exposing the at least a portion of the solid particlescomprising deposited coke to gasification conditions results incumulative deposition of less than 0.1 wt % of metals on the gasifierwall, relative to the feedstock's cumulative metals content.
 15. Themethod of claim 1, wherein passing at least a second portion of thepartially gasified solid particles from the gasifier to the reactorcomprises a) passing at least a second portion of the partially gasifiedsolid particles from the gasifier to a coking section of the reactor; b)passing at least a second portion of the partially gasified solidparticles from the gasifier to a stripping section of the reactor; or c)a combination of a) and b).
 16. The method of claim 1, wherein thegasifier comprises a single gasifier reactor.
 17. The method of claim 1,wherein the oxygen-containing gas comprises air, and wherein the gasphase product further comprises N₂ from the air.
 18. A system forperforming fluidized coking, comprising: a fluidized bed cokercomprising a reactor, a reactor coker feed inlet, a reactor cold cokeoutlet, a reactor hot coke inlet, a reactor liquid product outlet, and afluidized bed of solid particles within the reactor, the fluidized bedof solid particles comprising a first portion of solid particles havingpotassium carbonate, calcium oxide, or a combination thereof supportedon the first portion of solid particles; and a gasifier comprising agasifier coke inlet in fluid communication with the cold coke outlet, agasifier coke outlet in fluid communication with the hot coke inlet, atleast one gasifier input gas inlet, a fuel gas outlet, and a secondportion of solid particles.
 19. The system of claim 18, wherein thefirst portion of solid particles comprises coke particles.
 20. Thesystem of claim 18, wherein the second portion of solid particlescomprises partially gasified coke particles.
 21. The system of claim 18,wherein the first portion of solid particles comprises potassiumcarbonate, calcium oxide, or a combination thereof supported on arefractory oxide support.
 22. The system of claim 18, wherein thereactor comprises a coking zone and a stripping zone, wherein a) thegasifier coke outlet is in fluid communication with the coking zone viathe hot coke inlet, b) the gasifier coke outlet is in fluidcommunication with the stripping zone via the hot coke inlet, or c) acombination of a) and b).
 23. The system of claim 18, wherein thegasifier comprises a single gasifier reactor.